The present invention relates generally to an exhaust manifold reactor assembly for the exhaust system of an internal combustion engine and more specifically to an assembly which comprises a cylindrical reactor casing having an internal concentric core mounted therein. The invention is particularly concerned with the arrangement for mounting the core.
Generally speaking, a manifold reactor is used to eliminate through oxidation the noxious contents (for example, hydrocarbons or carbon monoxide) which might otherwise be contained in the exhaust gases of an internal combustion engine. In order to effect the oxidation of the noxious contents, the manifold reactor is equipped with a recombustion chamber whose temperature is maintained as high as possible. For this purpose, an insulating material is disposed on the outer periphery of the recombustion chamber to thereby minimize heat emission from the recombustion chamber.
Since the core defining the recombustion chamber is exposed to such a high temperature whereas the reactor casing supporting the core has a relatively low temperature, it is generally difficult to effect fixed connection between the core and the reactor casing in plural positions. This is because thermal expansion having different values between the reactor casing and the core occurs.
Therefore, the conventional connection between the reactor casing and the core of the manifold reactor has been accomplished fixedly in one longitudinally central position. In another position, however, the connection is accomplished such that the projections formed on the reactor casing are made to abut against the core.
However, support of the core by such connections is not sufficient for protecting the manifold reactor from vibrations from the internal combustion engine or the like. Fixed contact between the reactor casing and the core invites vibrations in the core, which in turn results in breakage and dislocation of the insulating material. This may further result in breakage of the core itself. These undesirable phenomena are promoted by the thermal expansion of the core. As a result, the conventional manifold reactor does not exhibit a sufficiently long service life.
It is, therefore, an object of the present invention to provide an exhaust manifold reactor assembly which is free from the above-described disadvantages and which can enjoy prolonged life and stable operation.
Another object of the present invention is to provide an exhaust manifold reactor assembly which exhibits substantially reduced noise levels.